If vacuum gauge is read over 0.3 Mpa in clause 3) above, give up starting engine, or start it at a low speed.

5)

When pump is operated and water is discharged, the faster pump runs, the lower vacuum meter is read. Here, it is important not to let pressure decrease below 0.05 Mpa by decreasing speed or replacing nozzle with one having smaller diameter. (If static pressure is over 0.15 Mpa, the figure on vacuum meter will not drop below 0.05 Mpa in most cases.)

6)

When the figure of vacuum meter pressure is more than 3/4 of static pressure when pump runs to discharge water, another pump can be additionally connected to the same hydrant.